Sheet-metal reservoir and method of making the same



July 24, I 1923- HOFFMAN SHEET METAL RESERVOIR AND METHOD OF MAKING THE SAME Filed June 19, 1920 Patented July 24, 1923.

-UNITED STATES 1,462,640 ATENT OFFICE.

RUDOLPH HOFFMAN, OF KANKAKEE, ILLINOIS, ASSIGNOR TO SEARS, -ROEBU' CK AND 00., or CHICAGO,

ILLINOIS, A CORPORATION OF NEW YORK.

SHEET-METAL RESERVOIR AND METHOD OF MAKING THE SAME.

Application filed June 19, 1920. Serial No. 390,059.

To all whom it may concern Be it known that I, RUDOLPH HOFFMAN, a citizen of the United States, residing at Kankakee, in the county of Kankakee and State of Illinois, have invented certain new and useful Improvements in Sheet-Metal Reservoirs and Methods of Making the Same, of which the following is a specification.

The invention relates to reservoirs of the type used upon cook stoves for containing water to be heated; and the principal object of the invention is to provide a reservoir which may be constructed entirely of sheet dill metal in a novel and advantageous manner and at a relatively low cost.

Reservoirs of the type indicated have in the past been made to alarge extent from copper by a deep-drawing process, the copper being provided with a suitable finish, such as tin or nickel; but the cost of such reservoirs has become so great as to render their manufacture almost prohibitive. Reservoirs made of sheet steel provided with a coating ofenamel for the sake of cleanliness are desirable but. to form the reservoir, by deep-drawing from sheet steel of sufiiciently heavy gage to withstand the extreme heat in the enameling process without warping, has in the past if not impossible, Moreover,'the cost of the equipment required is very great.

The object of my invention, more specifically stated, is to produce a reservoir which may be made of sheet steel in such a manner as to overcome the difiiculties above set forth and without sacrificing any of the advantages accompanying prior methods of construction.

In carrying out my invention, I form the reservoir from a blank of sheet metal consisting of a main or central portion and. opposed side portions, by deep-drawing the central portion to provide a bottom wall for the reservoir and upturned edge walls, thus forming the lower'portion of the reservoir so as to eliminate sea-ms at the lower corners thereof; and bending the opposed wing portions upwardly from the edge walls of the lower portion, and joining the edges of the wing portions as by electric welding, to provide the side walls for the upper portion of the reservoir. The making of liquid-tight seams between adjoining sidewalls of the upper portion of the reservoir presents no been difficult difiiculties, while the lower portion of the reservoir is made seamless so that the difficulties previously attending the eflective sealing of the joints at the lower corners, in the formation of reservoirs from a blank by merely bending the metal, are effectively overcome.

In the accompanying drawings, wherein I have illustrated a preferred embodiment of my invention, Figure 1 is aperspective view of a completed reservoir. Fig. 2 is a plan view of a blank from which. the reservoir is constructed. Fig. 3 is a perspective view on a larger scale showing the blank after the first or deep-drawing operation. Fig. 4 is a fragmentary perspective view illustrating a detail of construction. Fig. 5 is a fragmentary view illustrating the manner of' welding electrically overlapping edges of the portions of the blank bent to provide the side walls of the reservoir.

Referring to Fig. 1, the completed reservoir comprises a lower seamless portion 7 consisting of a bottom 8 and up-turned edge walls 9; and an upper portion 10 consisting of opposed side walls 11 and 11 joined by seams 12 at each of the corners of the reservoir. At the upper edges of each of the side walls 11 and 11 are provided outturned flanges l3 and 13 connected at the corners of the reservoir by corner plates 14.

Referring now to Fig. 2 of the drawings, A. designates generally the blank from which the reservoir is formed. Preferably the material used is sheet steel of sutliciently heavy gage to withstand the intense heat to which the metal is subjected in the enameling process. Said blank consists of a main or central portion a, and a plurality of oppositely disposed side or wing portions. Herein the central portion a is rectangular in form and four wing portions are provided, the adjoining wings being designated 7) and c.

In the first'operation (Fig. 3) the central portion a is deep-drawn to provide the lower portion 7 of the reservoir consisting of the bottom wall 8 and edge walls 9. The wing portions Z) and 0 of the blank are then bent upwardly in continuation'of the edge walls 9 to form the side walls 11 and 11 of the reservoir (Fig. 1). Preferably said wing portions 1) and a are provided at their opposite side edges with edge portions. b and 0 which are bent at substantially right angles tight seams 12.

' will be apparent to the wing portions to form laps l5 and 1.5. It will be observed that the laps 15 and 15 of adjacent wing portions are adapted to engage respectively with the inner and outer surfaces of adjoining walls 11 and 11? and are secured together to form the liquid Preferably this is accomplished by electric welding (Fig. 5).

If desired, the means for eflecting the formationof the seams 12 by welding may comprise a stationary electrode 16 and a movable electrode 17 adapted to roll upon the electrode 16. The eoacting edges of the electrodes are suitably shaped to receive the overlapping portions of the adjoining wing portions 2) and 0, as shown in Fig. 5. It

that in the welding operation the softened metal may be rolled in a manner to provide a very eflicient joint between the side walls 11 and 11. Furthermore, by the elimination of all seams atthe lower corners of the reservoir, the difficulty which would otherwise be experienced is overcome.

At their extreme outer edges the wing portions 6 and c are provided with end portions (2 and d which are bent outwardly to provide the flanges 13 and 13" at the upper edges of the side walls 11 and 11 of the reservoir.

The corner plates 14 which secure the flanges of adjoining walls together may also secured in position by electric welding. Preferably the exposed central portions of said corner plates are shaped to lie flush with the upper surfaces of the flanges 13, while the end portions of the plates are secured to the under sides of said flanges.

Itwill be seen that I have produced a reservoir. which may be constructed of sheet steel or other metal in a novel and advantageous manner. The operation is extremely simple, the cost of the necessary equipment relatively low, and the completed reservoir is of a highly efficient character.

While I have herein described the invention with considerable particularity, it is to be understood that I do not thereby intend to limit the invention to the particular embodlment illustrated, since -it is contema platedthat various changes in construction and arrangement may be made without departing from the spirit and scope of the invention as expressed in the following claims.

claim as my invention:

1. A sheet metal reservoir formed from a blank having a central portion deep-drawn to. provide a seamless lower portion for the reservoir consisting of a bottom wall having upturned edge walls, and wing portions bent upwardly from and in continuation of said edge walls and joined to provide the side walls of the reservoir.

sheet metal reservoir formed. from a blank having a central portion deep-drawn to provide a seamless lower portion for the reservoir consisting of a bottom wall having upturned edge walls, and wing portions bent upwardly from and in continuation of said edge walls and joined to provide the side walls of the reservoir, said wing portions each having a lap engaging with an adjoining wall and secured thereto as by welding.

A reservoir made wholly of sheet metal and comprising a. lower seamless portion providing a bottom wall and edge walls, and an upper portion composed of separate sections formed integral with said edge walls of the lower portion ofthe reservoir and secured together at adjoining edges to provide fluid-tight joints.

4 Areservoir made wholly of sheet metal and comprising a lower seamless portion providing a bottom wall and edge walls, and an upper portion formed in continuation of said edge walls of the lower portion of the reservoir and joined together at adjoining edges to provide fluid-tight seams, each of the adjoining edges of the walls having a lap bent at substantially right.

angles with reference thereto and secured to the adjoining wall as by welding.

5. A reservoir made whollyof sheet metal and comprising a lower seamless portion prgviding a bottom wall and edge walls, an Wing portions integral with said edge walls of the lower portion of the reservoir and joined together at adjoining edges to provide fluid-tight seams, said walls of the upper portion of the reservoir each having an out-turned flange at its upper edge, and corner plates for securing the flanges of the adjoining walls together.

reservoir formed from a blank of sheet metal comprising a central portion and opposed wing portions,-said wing portions being bent upwardly from the main portion and secured together at their adjoining edges to provide side walls for the reservoir, the upper edges of said side walls having out-turned flanges, and corner plates secured at their opposite ends to the under sides of adjoining flanges and having central portions substantially flush with the upper surfaces of the adjoining flanges.

7. A sheet metal reservoir comprising a deep-drawn seamless lower portion, an upper portion comprising side walls secured together at adjoining edges as by electric welding, one of each pair of adjoining walls having a flange overlapping the other wall and secured thereto as by welding.

8. The method of maln'ng sheet metal reservoirs which consists in -forming a blank having a main or central portion and opposed wing portions, shaping the central portion by a deep-drawing process to form the bottom wall of the reservoir and upan upper portion formed from opposed turned edge walls thus providing a seamless lower portion for the reservoir, bending the wing portions upwardly from the edge walls of said lower portion and in continuation thereof, with their adjoining edges in overlapping relation, and finally securing the overlapping edges of the wing portions together as by electric welding to form a seam or joint.

9. The method of making sheet metal reservoirs which consists in first forming I from a blank of metal a lower seamless portion by a deep-drawing process so as to provide a bottom wall and upturned edge walls,

15 and completing the formation of the resermy hand.

RUDOLPH HOFFMAN. 

